Upgrade to the latest dev version. Your computer is far better than my own, and I don't get slowdown in the rain at 5xIR 2xAA in Wind Waker, so you should probably upgrade your revision. For context on this, there have been a lot of speed improvements and accuracy improvements that affect Wind Waker heavily, and the game runs faster, more stable, and less messed-up in the latest revision with HLE than 4.0 with LLE.
in a perfect world we would all be piles of sand with no ability to form coherent bodies of body